Apparatus for reducing ores.



H. N. TRACY. APPARATUS FOR REDUCING ORE-S. APPLICATION FILED 1AN.1I.1911.

Patented Sept. 17 1918.

w m w I HARMON N. TRACY, F LOS ANGELES, CALIFORNIA.

APPARATUS FOR REDUCING ORES Specification of Letters Patent.

Patented Sept. 17, 1918.

Continuation of application Serial No. 23,548, filed April 24, 1915.This application filed January 11, 1917'. Serial N 0. 141,820.

To all whom it may concern: j

Be it known that I, HAR'MoN N. TRAoY,'a citizen of the United States,residing at Los An eles, in the county of Los Angeles, State ofalifornia, have invented new and useful Improvements in Apparatus forReducing Qres, of which the following is a specification.

My invention relates to a method and ap paratus for reducin ores;,myobject being the provision of slmple, direct, and eflicient method andapparatus for reducing various forms of ore, to obtain the metallicconstituents thereof in metallic form. It will be understood that mymethod and a-pparatus are not limited to any one particular species orclass of ores; but, for the purpose of the following specification, Ishall explain my method and apparatus as applied to iron ores which areoxide or which may be roasted to oxids in the presence of air. Thisapplication is a continuation in part of my application S. N. 23,548,filed April 24, 1915, on apparatus for reducing ores. In thisapplication I carry on and claim those features of my former applicationthat refer particularly to the shape, format-ion, etc., of the orereducing. stack; and 'in a copending application Serial N 0. 151,629,tiled March 1, 1917, on apparatus for reducing ores I specifically carryon and claim those matters that, in my former application, re-

ferred to combinations with the cooling chamber, etc.

It is a primary object of my invention to provide a practicable methodwhereby such ores may be reduced in a continuous one way flow or in acontinuous stream flowing in one direction. I am aware that such oreshave heretofore been reduced by treatment in batches, but, to myknowledge, no simple and practicable means has yet been evolved fortreating such ores continuously.

The primary features of my invention inelude a means for treating oresin a comparatively long and narrow vertical column by injecting areducing. fluid, say, hydrocar bon gas, into the central portions of thelong and narrow column of ore. It is a particular feature of myinvention that no products of combustion of" a heating furnace come intocontact with the column of ore, and also that atmospheric air isexcluded from the treatment zone in the column by the arrangement of thecolumn itself; i..e.,

therethrough without choking.

the column being long and narrow, the re ducing gases at first displaceand thereafter continuously exclude the atmospheric air, so that thereducing action is carried on in the total absence of free oxygen.

There are other features of my invention which are particularly setforth in the following specification, reference being had to theaccompanying drawings, in which, for the purpose of this specification,I have shown a typical and preferred form of ap paratus, and in whichdrawings, Figure l'is a sectional elevation showing my improvedapparatus, Fig. 2 is a section taken as indicated by line 22 on Fig. 1,and Fig. 3 is a section taken as indicated by line of Fig. 1.

In the drawings I have shown a relatively long and narrow vertical orestack 10, the dimnsions'of which may be typically as folfeet, andinternal diameter approximately thirty-three inches at the top andthirty-six inches at the bottom. The stack is made slightly larger atthe bottom in order to facilitate the free passage of ore downwardly Itis one of the features of my invention that the ore passes through thestack 10 under gravitational influence in such a manner that the stackcan be constantly kept full of ore and for. this purpose I prefer tomake the stack vertical, although it may extend diagonally verticallyand still have the advantage of the ore .moving therethrough undergravitational influence. -I provide a means for heating the ore which isdcliveredto the upper end of the stack and I prefer to heat the ore asclose to the upper end of the stack as possible and to deliver the oredirectly into the stack with the least loss of heat. Preferably, forthis purpose I provide a re volving roasting drum 11 of any preferreddesign, the discharge end 11 of the drum projecting into the upper end10* of the stack. The drum is placed at a suitable incline so that orefed into its upper end ll from the feed spout 12 will pass downwardlythrough the drum. A furnace or burner apparatus 13 supplies heat to theroasting around the flame, as indicated in the draw- I 16 or any Controlof the burner is had by valve other suitable means. A draft stack isshown at 17 connecting with the upper end of the roasting drum 11. Thespout 12 leads from any suitable bin 18 and the feed of ore iscontrolled by a revolving roller 19 operated by motor 20, which motor iscontrolled by a controller 21 onthe switch board 22. This switch board22 is mounted in a convenient position on the platform 23, said platformbeing preferably supported at the upper end of the stack. As hereinafterexplained, the operation of my apparatusis under control of a single manon the platform 23. a

The drum 11 and furnace 13 not only perings.

forms the function of heating the ore directly-prior to its delivery tothe upper end 10 of the stack 10, but also performs the function ofroasting and oxidizing the ores which must preferably be changed tooxids before they are reduced in the reducing stack 10. However the oresare delivered to the drum 11, it will be presumed (for the purpose ofthis specification) that they are delivered to the'upper end of thereducing stack in the form of oxids; and the ores are end of thereducing stack in highly heated condition. The temperature of the oresis governed by conditions hereinafter stated. 1

The stack is provided at suitable intervals with cross-bars 25, formingrabblers for causing the pieces of ore to move relatively to each otherand to prevent the ore from settling into a solid mass in the stack. At

' the lower end of the stack '1 provide an accumulating and coolingchamber 30 of suitable capacity for holding such a quantity of reducedproducts that coolin can be effectually carried out before the nalproduct is taken out to atmosphere; that is, cooling below the point ofoxidation. I prefer to arrange the cooling means as indicated in thedrawings, comprising a number of transverse tubes 31 and 31 arrangedacross the cooling chamber. These tubes may be inclined'upwardly towardthe center as shown at 31, or may extend straight across the chamber asshown at 31. even distribution of the material over' the whole chamber'30. I refer to make at least the upperrows of tu es in this shape. Atone end of the tube I employ a blower fan 32 of any preferred design toprovide a forced draft through the tubes; and the other ends of thetubes may communicate with a chamber 33 from which a draft stack 34arises. This draft stack extends upwardly around the central reducingstack; and the hot air passing upwardly through the draft stack aidsmaterially in keeping the reducing stack'at proper temperature, formingan insulation zone around the reduction stack,

' The heat carried into the furnace by The inclined tubes aid in thewhich are at the highest temperature, may

connect with a draft pipe 35 -which extendsupwardly and. discharges intothe air box 36 of furnace 13. The air thus delivered to the furnace ishighly heated; and ,1 preferably supply all the air to the furnace 13 inthis manner, providing a damper 37 which may be controlled by theoperator on platform t 1s heated air is' thus utilized in the heatingand roasting process in the drum 11.' It will be noted that, by thearrangement herein described, I return a considerable part ofthe heatcarried by the reduced products to the unreduced ores, this certain partof the heat remaining in the system and not being lost.

At the lower end of the cooling chamber 30 I place a suitable dischargeconveyer/1O operated by motor 41 controlled by suitable controller 42 onswitch board 22. When my apparatus. is in operation the attendant on theplatform 23'has full control of the introduction and withdrawal of oreto and from the stack 10; and by re lating the introduction andwithdrawal Tl; may regulate the rate of flow of ore through the stack,and

thus regulate the time element of the reducing action. The introductionand withdrawal are so regulated that, with the proper rate of flow, thestack 10 is kept constantly full of ore which moves downwardly under theinfluence of gravitation at a uniform rate, moving downwardly into thereduction zone and then on downwardly out of the reduction zone into thecooling chamber below,

and thence out through the conveyer 40 into any suitable conveying meansor storage bins or the like. I

The re-agent employed for reduction may be varied to suit particularrequirements; I have preferred to show and describe herein a means forintroducing hydro-carbon, coal or water gas or the like to the centralparts of the reduction stack 10. I may employ a holder or tank 50 intowhich the prepared. gas is passed and from which the gas is taken by asuitable compressor or blower 51 and forced through the pipe 52 to thedistribution pipes 53. I may arrange a plurality of'sets of such pipes53, controlled by any suitable valves 54, so that the reducing gas maybe admitted to any or all of the sets. The pipes 53 extend across thestack 10 and have suitable outlets 55 on their under sides so that theoutlets will not be choked by the downwardly moving ore. The exact pointof introduction'of the gas is controlled by the proper manipulation ofthe valves 54,

while the amount of gas supplied is regur' lated and controlled bycontrolling the compressor driving the motor 56 from the controller 57on switch board 22. Proper pressure 1s maintained on the gas to causeits dlstrlbution through the ore in the reducing amount of condition;and

zone at the central portions of'the'stack. The

gas to be supplied must be sufficientto reduce the ore wlthin the timeperiod taken for the ore to pass vertically through the reduction zone.that zone in which the ing both upwardly and downwardly from the pipes53, re-acts upon the ore to cause its reduction. Below the reductionzone there is a constantly-downwardly moving stream of reduced metal,while above the reduction zone there is a constantly downwardly movingmass of unreduced but highly heated ore. As hereinbefore stated, the oredelivered from the roasting drum is in highly heated the operator kee sthe temperature of the ore at the most efli that is, at that temperatureat which reduction will most efficiently take place. To enable anaccurate control of the temperature I may provide pyrometers at variousplaces v in eters having indicators 62 and 63 on switch the stack, as at60 and 61, these pyromboard 22. he operator can accurately control thetemperatures so as to, obtain the proper temperature at and in, thereduction zone; whether the total reduction action, in-

' eluding the breaking up of the oxids and the combination of theiroxygen with the reducreduction zone chamber becomes filled with the ingits nature. In the one case the oreabovethe is further heated by thesurplus of heat arising from an exothermic ac tion; while in the other asurplus of heat must be supplied from the furnace 13. The

outward spread of the reducing gas in the relatively narrow stack drivesout and dis-.

places atmospheric air and thus excludes free oxygen entirely from thereducing zone and from the whole stack. When the apparatus is in fulloperation, the cooling gaseous products of reduction, and the metal isthus cooled in the presence of a non-oxidizing gas. a o

I wish to particularly emphasize that feature of my invention whichincludes the relatively long'and narrow columnof ore, and theintroduction of the reducing agent at or near thelongitudinal center ofthe column; under such conditions, as herein exampled, that the reducingagent displaces and excludes atmospherlc all so that the reaction mayproceed exactly as in an air-tight chamber. I wish also to callparticular attention to various subsidiary features of my method and aparatus, including the direct delive of'the eated ore to the upper endofthe The reduction zone is reduct on gas, spreadcient point,

agent, is exothermic or endothermicin embodying a relatively long andnarrow vertical stack substantially open from end to end and free fromconstrictlons so that ore may move therethrough under gravitational,action, means to continuously introduceore to the upper end of thestack, means to' continuously withdraw the product from the lower end ofthe stack, means to control said introducing and withdrawing means so asto keep the stack continuously full of ore, and means tocontrollably'introduce a gaseous reducing agent to the ore exclusivelyat,the middle portion of the stack, whereby a constant zone of reducinggas is maintained at the middle part of the stack protected fromatmosphere by the material in the stack above and be 2. Ore reducingapparatus,

embodying a relatively long and narrow vertical stack substantiallyunobstructed and of substan tially uniform diameter from end to end andfree from-constrictions, means for continuously introducing ore to theupper end of the stack, means for controllably continuously withdrawingmaterial from the lower end of the stack so that the stack may be keptfilled with ore and material moving downwardly by gravitation, and meansto introduce a fluid reducing agent to the stack and ore at its middleportion.

3. The herein ing ores, embodying first continuously heating the ore,then continuously introducing the heated ore into a vertical columndevoid of constrictions from'the top to the bottom thereof, continuouslyintroducing a reducing agent near the central art of the column, andcontinuously with rawing reduced ore at the bottom of the column, therate of introduction and withdrawal of the ore being such as to keep thecolumn oforejconstant,

In witness that I claim the foregoing I have hereunto subscribed my namethis 28th dayrof December, 1816.

H. N TRACY,

described method of reduc-

